1. Field of the Invention
The disclosure relates to a heart support device for pulsatile delivery of blood.
2. Discussion of the Background Art
Heart support devices, particularly mechanical systems for support of the blood circulation (VAD: Ventricular Assist Device) are implanted into the body of a patient suffering from cardiac insufficiency. Such devices will take over a part of the pumping work, thus stabilizing the blood circulation, e.g. until a donor organ has become available. Recent search has revealed that, during use of a heart support device, the cardiac function can improve to an extent favorable enough to allow for explanation of the system without subsequent heart transplantation.
Artificial heart pumps can be adapted to the most diverse requirements and, in contrast to donor hearts, are readily available without a waiting period. However, such heart support devices have to meet high demands with regard to the chosen technology and the tolerability of the implants. For instance, the blood may happen to be damaged by the pumping work. The power supply to the electrically operated systems, e.g. via cables passing through the abdominal wall, harbors a considerable risk of infection to the patient. Further, low degrees of efficiency will cause high energy consumption and will heat the surrounding tissue. Often, the assisted blood circulation has to be maintained through months or years. The systems are subjected to strong mechanical stresses. Since it is not possible to exchange blood pumps quickly, such pumps must have a very high failure safety.
DE 40 201 20 describes a heart support system which is operated hydraulically. A displacement pump is provided for pumping a hydraulic liquid alternately into a first and a second hydraulic chamber, the hydraulic liquid being separated by a flexible membrane from the blood-contained in the hydraulic chamber—that is to be conveyed. By filling the first hydraulic chamber with hydraulic liquid, the blood within the chamber will be displaced and, via a valve, be conveyed into the circulation. The hydraulic pump is arranged between the two hydraulic chambers and partially within the hydraulic chambers themselves.
A disadvantage of the above described device resides in that the two hydraulic chambers, having two blood chambers arranged laterally adjacent thereto, as well as the hydraulic pump located between the hydraulic chambers, together have a large construction height and thus can be implanted into a patient's body only with considerably difficulty.
It is an object of the disclosure to provide a heart support device having a low construction height.